Dynamic modelling of planetary gearboxes using vibrational analysis

. Planetary gearboxes failure has been a major problem in
systems reliability, hence condition monitoring of this component is essential.
In order to identify faults, a dynamic model of the gearbox is
presented taking into account backlash and tooth cracks. Newtonian
equations of motion developed for a planetary gear is solved and modal
analysis for solving the lumped parametric differential equations of modelled
single stage planetary gearbox is adopted to observe the vibrational
responses and to compare with existing literature. This work focuses primarily
on the effects of stiffness and damping. The eigenvalue problem
has been solved to measure the natural frequencies and amplitude of the
system. Parametric studies using stiffness and damping results indicate
significant changes in vibrational signals when there is a crack present
on tooth. Simulation results also show the relation between increment in
backlash and high frequency responses in the resultant vibration.